固溶前冷轧压下率对Cu-Ni-Si-Mg合金组织与性能的影响

为了优化Cu-Ni-Si-Mg合金的轧制工艺参数,利用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、能谱(EDS)和X射线衍射(XRD)等手段,对固溶前不同冷轧压下率下的Cu-Ni-Si-Mg合金时效态的组织性能及拉伸断口进行了分析.结果表明:随着冷轧压下率的增加,Cu-Ni-Si-Mg合金的平均晶粒尺寸逐渐增加,屈服强度、硬度和延伸率先增大后减小,抗拉强度表现为先增大,后在710 MPa左右波动,再减小的趋势;压下率从94%增加到96%,晶粒尺寸从12μm增加到52μm,而抗拉强度变化较小,归因于低压下时Cu-Ni-Si-Mg合金的细晶强化和时效强化占主导,而大压下时第二相粒子均匀的时效析出弥补了因晶粒粗大而造成的抗拉强度损失;压下率为93%时,合金的断裂为单一的韧性断裂,压下率为97%时,合金的断裂由韧性断裂和沿晶脆性断裂组成.

Effects of cold rolling reduction before solution treatment on microstructure and property of Cu-Ni-Si-Mg alloy

In order to optimize the rolling parameters of Cu-Ni-Si-Mg alloy, Optical Microscope ( OM ) , Scanning Electron Microscopy( SEM) ,Transmission Electron Microscope( TEM) ,Energy Dispersive Spectrometer ( EDS) and X?ray diffraction ( XRD ) were used to analyze the mechanical properties and tensile fracture morphology of Cu-Ni-Si-Mg alloy with different cold rolling reduction before solution treatment. The results show that the grain size of Cu-Ni-Si-Mg alloy increased, the yield strength, hardness and elongation increased first and then decreased, The tensile strength increased at first, after about 710 MPa fluctuation, then decreased with the increase of rolling reduction;cold reduction increased from 94% to 96%,the grain size increased from 12μm to 52 μm, While the tensile strength changed slightly owning to fine?grain strengthening and aging strengthening of Cu-Ni-Si-Mg alloy plays a leading role at low reduction, while Homogeneous precipitation of second phase particles under high reduction make up for the loss of tensile strength which caused by coarse grains;the tensile fracture morphology of alloy shows dimpled rupture when 93%rolling reduction while mixture mode of dimpled rupture and intergranular brittle fracture is observed when 97% rolling reduction.